Esempio n. 1
0
  /**
   * Determine which locations in the PTA satisfy a (Boolean) expression. Note: This is rather
   * inefficiently at the moment. TODO: potentially use explicit.StateMC on dummy model eventually
   */
  private BitSet checkLocationExpression(Expression expr) throws PrismException {
    int i, n;
    BitSet res;

    // Labels - expand and recurse
    // (note: currently not used - these are expanded earlier)
    if (expr instanceof ExpressionLabel) {
      ExpressionLabel exprLabel = (ExpressionLabel) expr;
      if (exprLabel.getName().equals("deadlock"))
        throw new PrismException("The \"deadlock\" label is not yet supported for PTAs");
      if (exprLabel.getName().equals("init"))
        throw new PrismException("The \"init\" label is not yet supported for PTAs");
      i = labelList.getLabelIndex(exprLabel.getName());
      if (i == -1)
        throw new PrismException("Unknown label \"" + exprLabel.getName() + "\" in property");
      // Check recursively
      return checkLocationExpression(labelList.getLabel(i));

    }
    // Other expressions...
    else {
      List<Object> states;
      // Object[] state;
      states = pta.getLocationNameList();
      n = states.size();
      res = new BitSet(n);
      for (i = 0; i < n; i++) {
        // state = (Object[])states.get(i);
        State state = (State) states.get(i);
        if (expr.evaluateBoolean(state, nonClockVarMap)) {
          res.set(i);
        }
      }
    }

    return res;
  }
Esempio n. 2
0
  /** Model check a property. */
  public Result check(Expression expr) throws PrismException {
    Modules2PTA m2pta;
    Result res;
    String resultString;
    long timer;

    // Starting model checking
    timer = System.currentTimeMillis();

    // Check for system...endsystem - not supported yet
    if (modulesFile.getSystemDefn() != null) {
      throw new PrismException(
          "The system...endsystem construct is not supported yet (try the digital clocks engine instead)");
    }

    // Translate ModulesFile object into a PTA object
    mainLog.println("\nBuilding PTA...");
    m2pta = new Modules2PTA(prism, modulesFile);
    pta = m2pta.translate();
    mainLog.println("\nPTA: " + pta.infoString());

    // Check for references to clocks - not allowed (yet)
    // (do this before modifications below for better error reporting)
    expr.accept(
        new ASTTraverseModify() {
          public Object visit(ExpressionVar e) throws PrismLangException {
            if (e.getType() instanceof TypeClock) {
              throw new PrismLangException(
                  "Properties cannot contain references to clocks (try the digital clocks engine instead)",
                  e);
            } else {
              return e;
            }
          }
        });

    // Take a copy of property, since will modify
    expr = expr.deepCopy();
    // Remove property refs ands labels from property
    expr = (Expression) expr.expandPropRefsAndLabels(propertiesFile, labelList);
    // Evaluate constants in property (easier to do now)
    expr = (Expression) expr.replaceConstants(constantValues);
    // Also simplify expression to optimise model checking
    expr = (Expression) expr.simplify();

    // Do model checking
    res = checkExpression(expr);

    // Model checking complete
    timer = System.currentTimeMillis() - timer;
    mainLog.println("\nModel checking completed in " + (timer / 1000.0) + " secs.");

    // Print result to log
    resultString = "Result";
    if (!("Result".equals(expr.getResultName())))
      resultString += " (" + expr.getResultName().toLowerCase() + ")";
    resultString += ": " + res;
    mainLog.print("\n" + resultString + "\n");

    // Return result
    return res;
  }